93 2.2 ignition control module questions

My friend has a 1993 Chevy cavilier with a 2.2 engine. It only fires on two cylinders. He suspects it is the ICM. He also has a 94 parts car. The ICMs were different. One had more connectors than the other. Does anyone know any more about this?

If your saying he's using a 94 cav 2.2 for a parts car? The 94 probably has an up-integrated ignition system, the 93 should have a by-pass ignition system.

What testing has been done? Do you not have spark everywhere? If the two cylinders causing a problem are on the same coil, did you try swapping the coils, to see if the problem followed the coil? The parts book shows, the numbers for the coils on the 93 and 94 are the same.

Yes he tried swapping the coil on the two dead cylinders and it remained the same. Then he bought one from a junk yard and there was no fire. Im thinking the difference in the modules is from one being an RS. Would a tachometer read from the ICM and have more wires?

It is starting to look like the ignition module, if the test coil was good? The ignition module for the bypass ignition system and the module for the up-integrated system are two different animals.

bypass ignition system?
up-intergrated system?
Can you explain the difference to me? Id like to know as much as I can about this. Or, can you point me to an info. source?
Thanks

In general terms, with the bypass ignition system, under 400 rpms, the ignition module controls the spark timing, 400 rpms and over, the pcm uses a voltage on the bypass circuit, that tells the icm to use the timing signal from the pcm for spark timing. The crank sensor signal goes to the icm.

With the up-integrated system, the pcm controls the spark timing even during cranking. The crank sensor signal goes to the pcm.

The autozone site probably has more information, click on the vehicle repair guides and follow the links. I'm not sure if all their information is accurate?